Dental articulator.



D. ROBERTS.

DENTAL ARTIGULATOR.

APPLICATION FILED IEB.26, 1913.

Patented May 12, 1914.

WITNESSES I; VEZTOH v ATTORNEY open and closed positions.

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DIXIE ROBERTS, OF ARKANSAS CITY, KANSAS.

DENTAL ARTICULATOR.

device of this character which will embody many important improvementsin respect to the means for securing the models to the aw-frames of thearticulator.

The device of the present invention is intended to overcome thedisadvantages of the present commonly employed mode of securing theplaster models to the jaw-frames,

which present mode consists in investing the jaw-frames with saidmodels, without the; introduction of any feature which would tend in anywise to destroy or minimize the advantages incidental to the use of aclamp-:

commonly employed method referred to. In a word, the present inventionaims to provide a thoroughly practicable articulator wherein a clampingaction is substituted for the referred to present mode of securing themodels to the j aw-frames, the structure and correlation of the parts ofthe device being such as to satisfy exacting requirements incidental todental articulators with respect to simplicity of construction, readyadjust{ ment of the models, effective clamping of the models and otherthings peculiar to devices of this character.

In the accompanying drawings I have illustrated the preferred embodimentof my invention, but it will be understood that various changes may bemade in the details and that the important features of the in-j 'ventionmay be variously embodied without departing from the spirit of theinvention or i the scope of the subjoined claims.

In the accompanying drawings, wherein llke characters of referencedesignate llke parts 1n the several v1ews:F1gure 1 1s a side elevationof the articulator; Fig. 2 is a top plan view thereof; Fig. 3 is a rearend elevation thereof; Fig. 4 is a top plan view of the lower jaw of thearticulator showing in full and dotted lines respectively the relativelyadjustable parts of the jaw in their The upper jaw-frame of thearticulator as is usual preferably composed of two sepae Specificationof Letters Patent.

Application filed February 26, 1913.

mg action as compared with the present -Ward the lower frame. This stopPatented May 12, 1914. Serial No. 750,871.

rately formed parts, to wit, a model-carrying part A and a frame A whichsupports said model-carrying part. The lower jawframe is as is usualpreferably composed of a model-carrying part B and a frame B forsupporting said model-carrying part. These two frames are pivotallyconnected together by suitable means, as the cross shaft C for example,whereby the upper frame A, A may swing on a horizontal axis toward andaway from the lower frame B, B, as usual in this class of devices. Itwill be understood that these frames carry the plaster-of- Paris models,which are designated X and Y respectively, and said models areeffectively clamped upon the respective portions A and B by the meanshereinafter described. An adjustable stop carried by one of theseframes, suitably near the pivot shaft C, and

engaging a suitable part of the other frame is employed to adjustablyregulate the distance of approach of the upper frame topreferablyconsists of a headed sorew'D having a threaded engagement. with atransverse bar 6 at the rear end of the lower frame-member B andengaging the under side of the member A, of the upper frame, near therear end of the latter. Suitable provision is made for pivotallyadjusting the upper jaw-frame laterally and for length in order toadjust the upper model to the lower model to accord with the bite of thepatient, and for securing the parts of said frame in adjusted position.These results are preferably secured, as usual, by

forming one of the parts of the upper frame, the part A, for example,with a longitudinal slot at through which a set screw 6 extends, saidset screw being threadably engaged with the other part, A and serving asa clamping screw and as a pivot. As thus far described the presentarticulator does not and need not difier essentially from dentalarticulators already in use.

The model-carrying partsA and B of thejaw-frames are each dividedlongitudinally, whereby each of saidframes has two members, hereinafter,for convenience, called arms. The arms of the upper jaw-frame are marked1 and 2 respectively and the arms of the lower jaw-frame are marked 3and A respectively. The arms of each frame are mounted for relativepivotal adjustment toward and away from each other and are provided withprojecting lugs or flanges varying its which engage the oppositelongitudinal edges of the models. The flanges of the upper arms aremarked 5 and 6 and those of the lower arms are marked 7 and 8. Inpractice, it is preferred that one of the arms of each jaw-frame befixed and the other movable toward and away from In the accompanyingdrawings the arms 1 and 3 are each pivoted to swing upon a verticalaxis, the axes of such pivotal movement being indicated at 9 and 10respectively; and the arms 2 and i are fixed against movement toward oraway from the arms 1 and 3. For adjusting the arms 1. and 3, adjustingscrews 11 and 12 are preferably employed, said adjusting screwspreferably extending through bosses 13, 13 and 14, 14 projecting fromthe arms, these screws having threaded engagement with certain of thebosses through which they extend, the bosses 13 and 14, for example. Itis also preferred to subject the pivoted arm to spring action in onedirection, the adjusting screws 11 and 12 of the arms acting against thetendency of the springs. In practice, this spring action is preferablyin a direction which tends to press the pivoted arms away from the fixedarms, and it is also preferred in practice to employ coiled springs, as15 and 16, for example, to give the spring action referred to, saidcoiled springs being preferably mounted on the respective adjustingscrews 11 and 12 and hearing against the bosses.

The arms 1 and 2 preferably have their confronting faces cut away inorder to pro vide a space, 17 between them, and similarly the arms 3 and4: preferably have their confronting faces cut away to provide a likespace, 18. By thus cutting away the arms the area of contact between thefiat sides of the models and said arms is reduced, therebycorrespondingly reducing the extent of the portion of said flat sideswhich need to be trimmed to fit the arms: it being apparent that as themodels must set perfectly on the frames any decrease in the area of thecontacting surfaces of the models and arms correspondingly reduces theextent of trimming necessary to produce a perfect contact.

It should be understood that while it is not wholly essential to theinvention, considered in its broader aspects, to have one of the arms ofeach frame fixed against pivotal movement relatively to the other arm ofits frame, yet this is very greatly preferred for the reasons thatimportant advantages as regards simplicity of construction andprevention of lateral dis-arrangement of the upper and lower models fromtheir proper relative positions according to the bite of the patient isassured by having one clamping lug of each pair of such lugs fixedagainst any lateral movement or adjustment, it being apparent that ifboth the same.

lugs of each pair have movement toward each other in clamping the modelthe tendency to move said model from its proper lateral position withrelation to the other model will be pronounced and that this objectionis overcome, as well as the structure simplified by providing one fixedarm with a lug projecting therefrom.

In the preferred embodiment of the invention the fixed arm at (of thelower frame) is integral with the adjacent condyl member at of saidframe; and the arm 2 of the upper frame is provided with a lateralextension 2 at its rear end to which the arm 1 of said frame is pivotedat the point 9. It is also preferred to mount the lower frame B onseparated feet, 25, which will lift it sufficiently to give free accessto the head 12 of the adjusting screw 12, so as to facilitate theadjustment of the pivoted arm of said lower frame and enable saidadjustment to be conveniently made without raising the articulator fromits support.

I prefer to employ an adjustable back-stop for resisting any tendency ofthe lower model Y to move rearward after it has been clamped. Suchback-stop is not essential to my invention but when employed preferablyconsists of a longitudinally adjustable screw 20 having threadedengagement with a boss 21 carried by a transverse member 22 of the frameB and provided at its front end with a lug 23 for engaging the rear endof the model Y and at its rear end with a milled head 24 for conveniencein adjusting it.

Having thus described the invention what I believe to be new and desireto secure by Letters Patent, is

1. A dental articulator comprising a jawframe having a model carryingmember which is divided longitudinally to provide arms, said arms havingprojections to engage a model upon the frame, and being mounted forrelative pivotal adjustment, laterally, to clamp and release the model,and adjusting and holding means therefor.

2. A dental articulator comprising a jawframe having a modelcarryingmember which is divided longitudinally to provide arms, one of said armsbeing fixed and the other pivoted, said arms having projections toengage opposite sides of a model upon said frame, and adjusting andholding means cpnnected with the pivoted arm for movmg it toward andaway from the fixed arm to thereby clamp and release the model.

3. A dental articulator comprising a jawframe having a model -carryingmember which is divided longitudinally to provide arms, said arms beingmounted for relative pivotal adjustment, laterally, projections fromsaid arms to engage the model, means tending to move the arms relativelyto each other, and adjustable means acting in opposition to the latter.

4. A dental articulator comprising a jawframe having a model-carryingmember which is divided longitudinally to provide arms, said arms beingmounted for relative pivotal adjustment, laterally, projections fromsaid arms to engage the model, a spring tending to move the armsrelatively to each other, and an adjust-ing screw acting in oppositionto said spring.

5. A dental articulator comprising a jawframe having a model-carryingmember which is divided longitudinally to provide arms, projections fromthe arms to engage opposite sides of the model, one of said arms beingfixed and the other pivoted, a spring tending to move the pivoted armrelatively to the fixed arm, and an adjusting screw acting in oppositionto said spring.

6. A dental articulator comprising a jawframe having a model-carryingmember which is divided longitudinally to provide arms, projections fromthe arms to engage opposite sides of the model, one of said arms beingfixed and the other pivoted, said arms having bosses, an adjusting screwextending loosely through the boss of one arm an having threadedengagement with the boss of the other arm, and a coiled spring mountedon said screw and between said bosses and tending to move the pivotedarm relatively to the fixed arm, the adjusting screw acting inopposition to said spring.

7 A dental articulator comprising a jawframe having a model carryingmember which is divided longitudinally to provide Copies of this patentmay be obtained for five cents each, by addressing the Commissioner ofPatents,

arms, projections from the arms to engage opposite sides of the model,one of said arms being mounted for pivoted adjustment relatively to theother to clamp and release the model, adjusting and holding meansconnected with the pivoted arm, and an adjustable back-stop for engagingthe rear end of the model.

8. In a dental articulator, a lower jawframe one of whose condyl membersis provided with a forwardly extending arm fixedly connected thereto, asecond arm pivoted to said frame, said arms having projections to engagethe model, and an adjusting and holding means connected with the pivotedarm.

9. In a dental articulator, a lower jawframe comprising condyl members,a transverse member connecting the condyl members with each other at thelower end of said frame, an arm fixedly connected at its rear end to oneof said condyl members and projecting forward therefrom, a second armhaving pivotal connection at its rear end with the other condyl member,projections from said arms to engage the side of a model and anadjusting and holding means for the pivoted arm.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

DIXIE ROBERTS. Witnesses:

C. J. STOOKMANN, CHARLES LOWELL HOWARD.

Washington, D. G.

